What is a Pressure Gauge?
An analog Pressure Gauge is originally a mechanical instrument that visually displays the pressure of a liquid or gas.
There are different types of Pressure Gauges, such as standard coil spring gauges (Bourdon gauge), hydraulic gauges, diaphragm gauges, and membrane gauges. The most common gauge in the industry is the coil spring (Bourdon) type gauge. This gauge contains a curved tube that, with increasing pressure/force on the Bourdon tube, will become straighter. The Bourdon tube is connected to a pointer that indicates the current pressure in the system on the dial.
In addition, more and more high-quality digital gauges are being used, which display the occurring pressure in an integrated digital display.
What Types of Pressure Gauges Are There?
- Relative pressure gauge (most common and is essentially a differential pressure between the outside air (atmosphere, approx. 1 bar) and the pressure on the process connection)
- Differential pressure gauge (is the difference in pressure between the two connection points of the differential pressure gauge)
- Absolute pressure gauge (is the pressure on the process connection relative to absolute vacuum)
What Determines the Choice of the Pressure Gauge?
- Pressure range
- Size of the gauge
- Process connection
- Materials of the wetted parts
- Gauge filling
Pressure Range of the Pressure Gauge
The pressure range of the Pressure Gauge must be greater than the maximum expected pressure in the system (including peaks).
On the dial of our gauges, the pressure unit is displayed in "bar", "kPA", and/or "psi" (pounds per square inch). Usually, the best way to select a gauge is to first take the normal working pressure of your own system (e.g., 4 bar) and then choose a gauge with a range of about twice the normal working pressure of your system (in this case, 10 bars). There are a few reasons why this is generally the best approach for selecting a gauge. First, gauges are most accurate in the middle third of their measuring range, and second, if the pointer is in the middle (pointing straight up), it is easy to see that the system is operating at its normal working pressure.
However, there are still some other important factors to consider. The selected pressure range should not be too low, as the gauge can be damaged under extremely high pressure. A good practice is to choose one based on the type of pressure to which the gauge will be subjected. If the working pressure is mostly at the same level, choose a gauge that will most likely not exceed 3/4 of the measuring range. But in the case of changing pressure or pulsation, it is better to choose one that does not exceed 2/3 of its dial range
Accuracy of a Pressure Gauge
The accuracy of a gauge is defined in ASME B40.100 and includes the following classes D, C, B, A, 1A, 2A, 3A, and 4A, with 4A being the most accurate and D being the least accurate gauge. A gauge can be calibrated. For gauges with a separation membrane (e.g., for hygiene), we would also like to know the working temperature so that the gauge correctly indicates when the medium in the separation membrane is at temperature.
Size of the Pressure Gauge
The size of the gauge depends on the application, connection, and the desired reading distance. Common diameters are 40 mm, 50 mm, 63 mm, 80 mm, 100 mm, 160 mm, and 250 mm
Process Connection of the Pressure Gauge
Standard gauges have an external thread connection which often corresponds to a certain size of the gauge. For example, a 63 mm gauge is usually equipped with 1/4", and a copper and stainless steel, but monel, PTFE, and other materials are also available.
Gauges with or without Glycerin
There are dry gauges and filled gauges. The filling of the gauge is usually silicone or glycerin and serves multiple functions. The filling protects the gauge from mechanical vibrations and pressure pulsations and makes the reading easier. However, the filling also lubricates the internal mechanism of the gauge. Be aware that if the temperature becomes high, the filling should not boil!
Calibration and Repair of Gauges
You can also contact us for the overhaul, calibration, and repair of gauges.
An extensive range of explosion-proof gauges compliant with ATEX and IECEx regulations.
Gauges with Imprint/Logo
It is also possible to supply gauges with an imprint/logo according to customer preferences, optionally in color.
We have gauges for:
- Air pressure/Compressed air gauge
- Hydraulic gauges, often high pressure
- Gas pressure gauge, gas pressure gauge
- Gauge for your compressor
- Water pressure gauge, e.g., for your heating system
- Gauges for vacuum
The range of gauges includes:
- Stainless steel gauges
- Gauges with chemical seal
- Pressure differential gauges
- Deep-sea gauges
- Pressure recorders
- Digital gauges with power supply
- Digital battery-powered gauges
- Explosion-proof gauges
- Gauges with imprint of your logo
Gauges are often connected in the industry with gauge accessories such as a snubber or a siphon, which can be found at Ebora under accessories.
Gauge-related terms are: Gauge air pressure, Gauge operation, Water pressure gauge, Gas pressure gauge, Air pressure gauge, Gauge water pressure, Bourdon gauge, Gas gauge, Hydraulic gauge, Gauge with drag pointer, Gauge with certificate, Gauge for steam, Vacuum gauge, Gauge purchase, Digital gauge, Gauge 10 bar.
Stainless steel gauges, pressure recorders, deep-sea gauges, gauges with chemical seal, pressure differential gauges, digital gauges with power supply, explosion-proof gauges, and gauges with logo or imprint.